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MASB Mudsill Anchor for CMU Block

The MASB is a mudsill anchor designed specifically to anchor a mudsill to concrete block foundations or walls. The unique design eliminates problems associated with misplaced anchor bolts. The MASB easily installs into wet concrete-grouted CMU block for a time-saving alternative to anchor bolts.

Key Features

  • Offset design for use in concrete block applications
  • One-piece design, so there are no nuts and washers to lose
  • Unique design eliminates concerns about stud placement


  • 16 gauge


  • Galvanized or ZMAX® coating; see Corrosion Information


  • Use all specified fasteners; see General Notes.
  • Fill CMU cell with concrete grout first, then place MASB into the grouted cell and adjust into position. Attach mudsill to anchor only after the concrete grout cures.
  • CMU shall have a minimum f'm = 1,500 psi.
  • The MASB mudsill anchors were tested in standard 8" CMU.

Related Literature

Product Information Table

Fastener Production Information and Stuff & Things
Model No. Ga. Coating/Material Packaging Qty.
MASB 16 Zinc Galvanized, G90 1

Load Tables

    These products are available with additional corrosion protection.

MASB Mudsill Anchors Load  Table
  1. Loads have been increased for wind or earthquake loading, with no further increase allowed. Reduce where other loads govern.
  2. For uplift loads, provide attachment from mudsill to building's structural components to prevent cross-grain bending.
  3. For concrete stem wall applications, allowable loads are based on a minimum concrete stem wall width of 6".
  4. Fasteners: Nail dimensions in the table are listed diameter by length. For additional information, see Fastener Types and Sizes Specified for Simpson Strong-Tie Connectors.

Prescriptive Anchor Spacing

    These products are available with additional corrosion protection.

Prescriptive Anchor Spacing
  1. "Prescriptive" denotes designs per the IRC or conventional provisions of the IBC for wind speeds 140 mph or less, or for Seismic Design Category D and less (SDC E and less in IBC).
  2. Spacing is based on parallel-to-plate load direction only.
  3. Place anchors not more than 12" from the end of sill and splices per code.
  4. Grout-filled CMU (GFCMU) shall have a minimum compressive strength of f'm = 1,500 psi.
  5. Spacings apply to DF, SP, and HF sill plates.

Code Reports & Compliance